As a raw material for manufacturing the aforementioned honeycomb structure used for the filter, catalyst support, or the like, silicon carbide particles excellent in heat and chemical resistance can be used. However, the honeycomb structure of silicon carbide manufactured by extrusion, which is a general method used for forming a honeycomb structure, has problems of high manufacturing costs and the like.
To avoid these problems, there is a technology to reduce the manufacturing costs by sintering at comparatively low firing temperature (see, for example, Japanese Patent Laid-Open No. 2002-356383).
One of the reasons why the honeycomb structure of silicon carbide is expensive is that the honeycomb structure obtained by injecting a kneaded raw material into a die and extruding the same is likely to have defects such as fractures and small holes caused in ribs thereof and has sometimes low productivity.
Another one of the reasons for the expensive honeycomb structure of silicon carbide is, in addition to the occurrence of defects, that the silicon carbide raw material is expensive. A silicon carbide raw material generally used is for applications as abrasive powder and has a small range of particle size distribution as standardized by JIS R 6001. After the silicon carbide is classified in a manufacturing process, a large amount of material which does not meet the standard remains. This makes it difficult to reduce the costs.
Therefore, an object of the present invention is to reduce the manufacturing costs of the porous honeycomb structure made of silicon carbide by allowing a material which has not hitherto been used to be used is while maintaining a suitable incidence of the defects such as fractures and small holes of ribs, a suitable porosity, and the like.